1. Field of the Invention
The present invention relates to a touch panel and a touch display panel, in particular, to a capacitive touch display panel.
2. Description of Related Art
In recent years, with the rapid development of, for example, information technology, wireless and mobile communication, and information appliances, for the purpose of more convenience, lighter weight and more humanization, a touch panel has gradually replaced a keyboard and a mouse, and becomes a main input device of many information products. Generally, the touch panel is essentially divided into, for example, a resistive touch panel, a capacitive touch panel, an optical touch panel, an acoustic touch panel and an electromagnetic touch panel. For example, the capacitive touch panel may be divided into a self capacitive touch panel and a mutual capacitive touch panel according to a driving and a sensing manner thereof
The conventional mutual capacitive touch panel includes a plurality of first electrode series extending along an X-axis direction, and a plurality of second electrode series extending along a Y-axis direction, in which the X-axis direction is different from the Y-axis direction. When a user touches the touch panel through a finger, the capacitance between the first electrode series and the second electrode series may be varied, and such a variation signal is transmitted to a controller, and then a coordinate of the touched position is calculated. When the mutual capacitive touch panel is combined with a display panel to constitute a mutual capacitive touch display panel, displayed images on the display panel may be changed according to the touched position selected by the user.
Generally, in order to improve the sensing sensitivity of the touch panel, a spacing between the first electrode series and the second electrode series needs to be increased, such that the capacitance variation between the first electrode series and the second electrode series is increased, so as to strengthen the sensed signal of the capacitance variation. However, although increasing the spacing between the first electrode series and the second electrode series may strengthen the sensed signal of a touched point of a user, when the spacing between the first electrode series and the second electrode series is too large, the touched point cannot be correctly calculated by using an overlapped proportion of the adjacent sensed signals in combination with interpolation, since an overlapped region between the adjacent sensed signals is insufficient, so that the conventional touch panel fails to clearly determine the touch locus of the user. Specifically, when the user draws a straight line on the touch panel through the finger, the sensing linearity of the touch panel is caused to be poor, since the overlapped region of the adjacent sensed signals is insufficient.